Only 30.6% of American adolescents complete three routinely recommended vaccinations, new research has found, but that number varies widely by state.
The Advisory Committee on Immunization Practices recommends that, by age 17 years, adolescents complete three key immunizations: human papillomavirus (HPV), quadrivalent meningococcal conjugate (MenACWY), and Tdap.
Sara Poston, PharmD, senior director for health outcomes research at GlaxoSmithKline, said at a press conference during IDWeek, an annual scientific meeting on infectious diseases held virtually this year, that her team set out to determine how many teens were completing the vaccinations and how the number varied by state and by behavioral factors.
Completion of the vaccines means getting the HPV series (two doses for people aged 9-14 years at first vaccination or three doses for those aged 15 years or older at first vaccination), completion of the MenACWY series (two doses), and getting a Tdap vaccine (one dose).
Rhode Island has the highest rates
Some states are clearly doing better than others. Idaho had the lowest completion rate (11.3%; 95% confidence interval, 6.9%-18.0%), and Rhode Island had the highest (56.4%; 95% CI, 49.8%-62.8%).
In the 2018 National Immunization Survey–Teen (NIS-Teen), Rhode Island had the highest vaccination coverage rate in the nation for meningococcal vaccine (98.7%) and the second-highest coverage rate for Tdap (96.3%) for adolescents aged 13-17 years. Also in 2018, the state had the highest vaccination rates in the nation for the HPV series for both male and female adolescents 13-17 years of age (78.1%), well above the national average of 51.1%.
Researchers used information from the Centers for Disease Control and Prevention as well as 2015-2018 NIS-Teen data to estimate national and state-level completion rates by age 17. They then combined NIS-Teen data with public state-level data to evaluate what was driving or discouraging completion.
“The good news is, we found some variables that we consider actionable and can be used by states and local health departments to improve the rates,” Dr. Poston said.
Those include encouraging a health care visit at age 16 or 17, provider recommendations to families to get the HPV vaccine, and state-level mandates for the MenACWY vaccine.
Those who had a health care visit at 16 or 17 were more than twice as likely to complete their vaccines (odds ratio, 2.35; 95% CI, 1.80-3.07). Those for whom HPV vaccination had ever been recommended by a health care provider were more than three times as likely to complete their vaccinations (OR, 3.24; 95% CI, 2.76-3.80).
Other factors predictive of completing the vaccines included being Black or Hispanic and having Medicaid insurance.
At the state level, “living in a state with a mandate for the meningococcal ACWY vaccine in elementary or secondary school was also associated with likelihood of vaccination,” Dr. Poston said. Teens in states with mandates were 60% more likely to complete the vaccines than those in states without mandates. (OR, 1.6; 95% CI, 1.2-2.3)
Marielle Fricchione, MD, assistant professor of pediatric infectious diseases at Rush Medical College, Chicago said in an interview, “Teen vaccines are notoriously hard to get into kids because it’s hard to get them back into the office for second doses.”
She said that Illinois is one of the states with a two-dose mandate for MenACWY before entering 6th grade and 12th grade, which has kept vaccination coverage high.
Educating providers on how to recommend HPV vaccination is the biggest vaccine focus, she added.